
class BasicEq a where
   isEqual :: a -> a -> Bool
   isEqual x y = not (isNotEqual x y)

   isNotEqual :: a -> a -> Bool
   isNotEqual x y = not (isEqual x y)

instance BasicEq Bool where
   isEqual x y = x == y

data Color = Red | Green | Blue
             deriving (Eq,Show,Ord,Read)


